Year	Number of
1990	259.87
1991	260.88
1992	262.68
1993	271.06
1994	270.31
1995	273.54
1996	278.25
1997	280.6
1998	285.36
1999	283.4
2000	282.89
2001	281.61
2002	285.4
2003	291.28
2004	293.09
2005	294.75
2006	296.19
2007	297.81
2008	303.66
2009	311.75
2010	320.5
2011	326.55
2012	333.55
2013	341.34
2014	349.86
2015	358.97
2016	368.8